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1.
光催化剂利用太阳能可以充分降解生活及工业废水中的有机污染物。与其他传统方法相比,在催化效率、低毒、可回收性等性能上,有着无可比拟的优越性。半导体材料在吸收能量大于或等于其禁带宽度的光子后产生电子及空穴,经过一系列的反应,转化为具有强氧化能力的羟基自由基,来降解染料等工业废品。由于晶体结构缺陷及自身结构等特征,光生电子与空穴极易发生复合,使得产生的活性羟基自由基数量变少,减弱光催化能力。异质结构的存在,加速了电子与空穴的分离,延长电子空穴的存活寿命,对提高光催化活性有着重要的影响。  相似文献   
2.
模拟人工测量过程,设计了一种适用于气体测微传感器自动测量孔径的柔顺机构.该机构也适用于孔径分选以及小型轴类零件的自动装配等作业过程.  相似文献   
3.
This paper shows how a public media can effectively utilize its social capital, and integrate with different resources from the related non-profit organizations and corporations in public relations perspective. A case study of a high-popularity Taiwanese public traffic radio: Police Broadcasting Service (PBS) is conducted. The finding shows that the public radio can cost-effectively deliver health communication with the principle of social marketing.  相似文献   
4.
What does it mean for a private enterprise in China to be embedded in a family? Our purpose here is twofold: (1) use social network analysis to describe what it means for a firm to be embedded in a family, (2) reveal from the application a new kind of firm, not family, yet akin to family. Armed with data on a large probability sample of private enterprises — a third of which meet ownership and employment criteria of being family businesses — we uncover a category of “hybrid family firms” that look modern in the style of firms that exclude family, but operate socially in ways similar to family firms. Our conclusion from summary statistics on the sample is that there are no differences in average performance level or network advantage for the three categories of businesses: family firms, hybrid family firms, and family-excluded firms. The fact that CEOs of family firms and hybrid family firms more often turn to family as key business contacts is a fact about network composition that raises no question about network mechanisms. Whether the CEO turns to more or fewer family contacts, government help is more likely with stronger political connections, and business success and survival are more likely with a large, open network. That said, the look-modern, act-traditional hybrid family firms stand alone in prospering with a CEO embedded in a closed business network. Recognition of hybrid family firms adds to the literature’s illustrations of social network analysis used to distinguish types of businesses and business people, and extends the population of organizations within which governance and strategy are likely to be better understood when viewed through a family logic.  相似文献   
5.
By considering uncertainty in the attributes common methods cannot be applicable in data clustering. In the recent years, many researches have been done by considering fuzzy concepts to interpolate the uncertainty. But when data elements attributes have probabilistic distributions, the uncertainty cannot be interpreted by fuzzy theory. In this article, a new concept for clustering of elements with predefined probabilistic distributions for their attributes has been proposed, so each observation will be as a member of a cluster with special probability. Two metaheuristic algorithms have been applied to deal with the problem. Squared Euclidean distance type has been considered to calculate the similarity of data elements to cluster centers. The sensitivity analysis shows that the proposed approach will converge to the classic approaches results when the variance of each point tends to be zero. Moreover, numerical analysis confirms that the proposed approach is efficient in clustering of probabilistic data.  相似文献   
6.
指出了微小孔零件加工中存在的问题,从高速主轴、刀具、材料、加工工艺方面提出了实现微小孔加工的条件,通过几个微上孔加工的实例,说明对微小孔加工的可行性。  相似文献   
7.
避开求解波动方程的困难,利用量子统计的方法,直接计算轴对称Taub-NUT黑洞背景下玻色场和费米场的配分函数.然后利用改进的砖墙方法——膜模型,计算黑洞背景下的玻色场和费米场的熵.计算表明,黑洞的熵与视界面积成正比的结论只有在薄膜的厚度远小于截断因子或两者为同阶无穷小时成立,当无穷小薄膜的厚度远大于无穷小截断因子时,黑洞的熵有一个对数发散项,黑洞熵不再与视界面积成正比.  相似文献   
8.
结合工程施工实践,针对冻结孔施工中的井斜控制技术进行了初步应用研究,优化后的井斜控制技术成功地用于工程施工。  相似文献   
9.
结构洞:关系的制胜点   总被引:1,自引:0,他引:1  
结构洞理论是社会网络分析理论的一种。在现代公共关系关系取向的理论中认为,公共关系工作者在其社会网络中占据了结构洞的位置,拥有的关系资源是一种可以产生价值的社会资本,为不同的团体搭桥,保持与各方的友好关系从而达到既定的工作目标,实现工作价值。本文从社会关系的视角考察公共关系理论和实践中存在的结构洞现象,分析其积极和消极意义,为关系取向的公共关系理论范式提供相应的理论支撑。  相似文献   
10.
高校市场营销专业学生营销实践能力培养研究   总被引:8,自引:0,他引:8  
本文首先界定了营销实践能力的含义和构成,然后着重分析了我国高校营销专业学生实践能力缺乏的原因,并针对营销人才实践能力培养中存在的问题提出相应的解决的办法。  相似文献   
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